High O2 values at WOT ???

[cagri]

I have been tuning my car again recently now that I got cams put in and the weather is hot.

What I am noticing is that my O2 s are showing .98 at 4000 to .96 at 7000 rpm when going WOT.

I am getting my timing pulled to 5 - 7 when I go WOT around 3500 rpm and it steadily climbs to 19 around 7000 rpm with no dips. If I try to lean it out little bit to bring down O2 values I cannot get more than 17 timing at the top and my timing does not go up as fast, just to make sure I leaned it way out by %7 or so, and my timing dropped to 3 and got up to 13 around 6000rpm which is pretty low and my O2s were still showing .94 to .96.

I remember 5 - 6 months ago, my O2s used to read .92 - .94 with almost the same settings, is it the hot weather that is causing this or is my O2 sensor is going bad?

All pulls are made on 3rd gear(2nd gear reads 1.00V, very rich) at 16.5 psi on 92 octane gas with 650cc injectors on FPBig28. Car is 1998 GSX.

My S-AFC settings are -29 -28 -28 -27 -27 - 26 -26

 

[candela]

I got a suggestion for you dude....turn up your boost a little bit.

Iowa can't be to hot, yes the weather will cause shitty everything. Cooler it is the more acutal cylinder pressure you will have regardless of what your boost gauge says (even though it usually reads higher if the temp drops a bunch). How are you making the runs? Are you cruising in 3rd to about 3300rpm the punching it and logging or what? A lot of times (specially with a T28) going from a cruise and open timing to a blimp or dump on the throttle will mean very fast boost pressures and the ECU has to react pretty fast, sometimes causing timing to drop considerably, even if you have enough fuel there so it gradually rises, and we know the T28 spools pretty quick on a healthy motor.

Why dont you log a little lower in the RPM range as well? Try easing into the throttle at about 2700 and being on full throttle by 3000rpm, this should help a little and keep timing from dropping a bunch (if thats the problem...considering you do have 650cc's and only a t28 @ 16psi ).....

What are you using to see your o2 voltages? Do you have an EGT gauge? Have ou considered an afc2? The more rpm settings make things a LOT easier and smoother IMO. Anyhow, what are the NE points that your listed setting are at? You have f eulp pump and regulator?

 

[nine5raptor]

Iowa might be fairly hot right now as we are at 106 with a heat index of 117. You might think that is not too hot candela, but remember our winters here in MO can drop below 0 and we always have snow.